On-Cell Touch Noise Compensation Circuit for AMOLED Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
On-cell touch panels face noise interference from display components, leading to detection errors and reduced sensitivity, especially in thin AMOLED displays and flexible panels, due to increased self-capacitance and electrical inhomogeneity.
Innovation Solution
A noise compensation circuit comprising an integration circuit, noise storage circuit, and noise detection circuit that compares touch detection signals with threshold values to differentiate noise from effective signals, saves noise signals, generates an average noise, and transmits both to the integration circuit to produce accurate touch detection results.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the thickness of the touch control display panel is reduced to below 100 μm, then the overall device becomes thinner and more flexible, but the upper electrodes of the AMOLED display panel have more significant influence on the induced electric field, causing detection errors
Solution Approach 1:
The patent extracts and separates the noise signal from the touch detection signal by comparing multiple detection results. The noise detection circuit identifies outliers that deviate from the majority of detection results, effectively removing the influence of display panel electrodes on the induced electric field.
Solution Approach 2:
The patent uses feedback by comparing multiple continuous touch detection signals and using the majority result to correct individual detection errors. The noise detection circuit continuously monitors detection results and adjusts by identifying and excluding anomalous readings caused by thin panel interference.
2Device complexity
If the self-capacitance of the on-cell touch panel increases, then the touch panel structure is simplified, but the ratio of mutual-capacitance to self-capacitance decreases, causing reduction in sensing sensitivity
Solution Approach 1:
The patent applies feedback by continuously monitoring multiple touch detection signals and using statistical comparison to maintain detection accuracy. When self-capacitance increases and reduces the mutual-to-self capacitance ratio, the system compensates by analyzing multiple detection results and identifying the valid signal through majority voting, thereby maintaining sensing sensitivity despite the reduced capacitance ratio.
3Adaptability or versatility
If the touch panel is made flexible, then the device adapts to different form factors, but electrical inhomogeneity phenomenon caused by panel curvature further influences the accuracy of detecting touched points
Solution Approach 1:
The patent extracts noise signals caused by panel curvature from the touch detection signals. By comparing multiple continuous detection results and identifying outliers that deviate from the majority pattern, the system removes the influence of electrical inhomogeneity caused by flexible panel deformation.
Solution Approach 2:
The patent uses feedback mechanisms to continuously adjust detection accuracy on flexible panels. By monitoring multiple detection results and using majority voting, the system compensates for electrical inhomogeneity variations caused by panel curvature, maintaining accurate touched point detection despite flexibility-induced variations.
4Measurement precision
If noise compensation circuit is added to mitigate noise interference, then touch detection accuracy is improved, but device complexity increases
Solution Approach 1:
The patent introduces an intermediary noise detection circuit that mediates between the touch detection circuit and the display panel. This intermediary component compares multiple detection results, identifies noise signals, and extracts valid touch information, thereby improving accuracy without requiring fundamental changes to the basic touch panel structure.
Data Source
AI summary
The disclosure provides a touch control apparatus and noise compensation circuit and method thereof. The noise compensation circuit includes an integration circuit, a noise storage circuit, and a noise detection circuit. The noise detection circuit receives a plurality of continuous touch detection signals, and compares the touch detection signals with a first and second threshold values to generate a plurality of detection results. The noise detection circuit sets a plurality of noise signals to be saved in the noise storage circuit or transmits a plurality of effective signals to the integration circuit based on the detection results. The noise storage circuit generates an average noise within a time period based on the noise signals and transmits the average noise to the integration circuit. The integration circuit generates a touch detection result according to the effective signals and the average noise.